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Graminae
Common names
Jaragua, faragua or yaragua grass, puntero (South America),
veyale (Mali), senbelet (Ethiopia), yellow spike thatching grass (southern
Africa).
Description
A very variable perennial from 60-240 cm high. Panicle loose
and narrow up to 50 cm long, with slightly spreading or contiguous racemes
with shortly hairy or nearly glabrous spikelets 3.5-5 mm long. The rusty
brown hairs on the spikelets and the racemes terminally exserted from the
spatheoles distinguish it from H. filipendula and H. hirta (Napper, 1965).
The flowering stems have little leaf. The sheaths of the leaves enclose
about half the length of each internode, giving the culm and banded appearance.
Distribution
Throughout tropical Africa, but widespread in Central and South
America.
Altitude range
Sea-level to 2 000 m in Colombia.
Rainfall requirements
600-1 400 mm.
Drought tolerance
Good on retentive soils withstands a dry season of six
months in the llanos of Colombia and in Bolivia.
Soil requirements
Spain and Andrew (1977) found that the order of sensitivity
to high aluminium soils was Cenchrus ciliaris cv. Biloela, very sensitive,
H. rufa, Panicum maximum and Melinis minutiflora, somewhat sensitive, and
Paspalum plicatulum and Brachiaria decumbens, relatively insensitive. Prefers
black clays and latosols.
Land preparation for establishment
A fully prepared seed-bed gives best results, but it will establish
in a rough seed-bed or after a burn in natural grassland.
Sowing methods
The seed is broadcast or sown in 25-40 cm rows on a prepared
and fertilized seed-bed. Root-stocks can also be planted, and it can be
undersown in maize.
Sowing depth and cover
Broadcast seed and give it a light harrowing. The long, twisted
awns on the 'seed' make it difficult to drill.
Sowing time and rate
Sow in Honduras early January to May at 15-20 kg/ha.
Seedling vigour
Selection 601 at CIAT has good seedling vigour.
Vigour of growth and growth
rhythm
Growth is retarded when day-length is less than 12 hours, 15
minutes, during the growing season from October to April. Rattray (1973)
recorded dry-matter production over a three-year period in Panama.
Response to defoliation
It stands close grazing (Semple, 1970) if applied rotationally
and not continuously.
Grazing management
Jaragua grass must be grazed or mown so that the growth at
no time reaches a height of more than 15 cm. This is attained in Costa
Rica and Honduras by grazing at approximately one beast to 0.8 hectares
throughout the year (Hogaboom, 1952). It takes about two years to establish
a good stand by broadcasting seed, or four to five months if sown on a
well-prepared seed-bed. Do not graze or cut within the first six months.
Flowering stands should be mown or burnt. Undergrazing and no burning favour
tussock formation and bare ground. A five-paddock system for beef breeding
stock, grazing seven days on and 28 days off from June to November, and
14 days on and 56 days off from December to May, is recommended.
Response to fire
It tolerates seasonal burning.
Dry-matter and green-matter
yields
At the Naitama Station, Colombia, under a six-week cutting
interval and 50 kg N/ha after each cut, leafy herbage accumulated to 75
cm or more, and contained 12-15 percent protein on a dry-matter basis.
Dry-matter production averaged 4 500 kg/ha per year (Crowder, Chaverra
& Lotero, 1970). In Honduras, 18 704 kg DM/ha was obtained at seven-week
cuts when fertilized with 555 kg/ha of 10:15:15 fertilizer (Kemp, Mackenzie
& Romney, 1971).°
Suitability for hay and
silage
It should be cut for hay and silage before flowering at a height
of 60-70 cm and four to five cuts are obtained during a growing season.
It has been used for silage in Minas Gerais (Brazil) (Alves & Silva,
1936). It makes good silage, but the fermentation is very slow.
Toxicity
Ndyanabo (1974) recorded 0.85 percent total oxalic acid in
the dry matter, but no toxicity.
Diseases
It has good disease resistance.
Main attributes
Its ability to persist, and to produce high live-weight gains
under heavy grazing demonstrates its value in African agriculture (Stobbs
& Joblin, 1966). A Panicum maximum/Stylosanthes guianensis pasture
at Serere gave 19 kg/ha more live-weight gain, but a H. rufa/centro pasture
gave 73 more grazing days in the same experiment.
Main deficiencies
It is rather coarse.
Frost tolerance
It is susceptible to frosts.
Ability to compete with
weeds
It competes successfully with weeds and smothers them.
Pests
It has no insect problem.
Palatability
It is not very palatable, especially as it approaches maturity
(Semple, 1970).
Response to photoperiod
It is a short-day plant.
Chemical analysis and
digestibility
In Costa Rica, H. rufa at floral initiation contained 3.65
percent crude protein, 33 percent crude fibre, 33.55 percent nitrogen-
free extract, 1.63 percent ether extract and 16.5 percent ash on a 10 percent
moisture basis (Gonzalez & Pacheco, 1970). In Panama, cut at six-week
intervals, it averaged 6-8 percent crude protein in the wet season and
4-6 percent in the dry season.
Natural habitat
Seasonally flooded grassland and open woodland.
Tolerance to flooding
It stands waterlogging and temporary flooding, but not permanent
flooding.
Fertilizer requirements
It gives a positive interaction with nitrogen and phosphorus,
with 112 kg nitrogen and 56 kg superphosphate per hectare the most efficient
application (Ortega, personal communication). However, it is one of the
better grasses under low nitrogen and low phosphorus conditions (CIAT,
1978). It will not tolerate more than 250 kg nitrogen per hectare during
the growing period.
Compatibility with other
grasses and legumes
It combines well with legumes.
Genetics and reproduction
2n=20, 30, 36, 40 (Fedorov, 1974).
Seed production and harvesting
It produces abundant viable seed from which it is easily established.
The stalks are cut off by hand in December (Honduras) in lengths of about
60 cm, dried in the field and then shaken to dislodge the seed, which must
then be well dried. Seed germination is about 25 percent, decreasing to
practically nil in ten months (Kemp, Mackenzie & Romney, 1971).
Economics
H. rufa is a common native pasture plant throughout East Africa
and Latin America, used mainly for beef cattle production. It has similar
characteristics to the H. contortus pasture in near-coastal Queensland,
without the troublesome awn. It is used in Africa as a coarse thatching
grass and as a general purpose straw, and produces a useful pulp for paper.
Animal production
At the El Nus Station, Colombia, on steep slopes, two-year-
old steers grazed on unfertilized H. rufa at one or two animals per hectare.
Animals gained 0.37 kg each per day at the lighter rate, but weeds encroached
because of low grazing intensity. At the heavier rate the animals gained
0.28 kg but the sward was damaged by heavy trampling (Crowder, Chaverra
& Lotero, 1970). In Panama, Rattray (1973) cited Ortega's recorded
live-weight gain of 0.30 kg per day from unfertilized grass and 0.45 kg
from grass fertilized with 90 kg each of phosphorus and nitrogen per hectare,
but it was uneconomic. A stocking rate of two 205-kg animals per hectare
was optimum for unfertilized grass.
Further reading
Tergas, Blue & Moore, 1971.
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